Pistons - flat or domed?

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I don't expect the demand is too high but 12-1 compression 920 cc sounds like just the ticket for a drag racer or high altitude motor. Jim
 
Just what I've picked up, Kevin Cameron's the likely source -

The less overall surface area, the better. That principle is compromised by the necessity of flow - chamber shape, valve size, valve pockets. Flow dictates domes, squish, and the like but such flow helpers typically add to the overall surface area and surface area transmutes motive gas pressure into heat transfer. Instead of pushing the piston down, pressure becomes heat, greater surface area helps assists its transfer into the head and the piston. Leaving flow considerations aside, just focusing on minimum surface area, a sphere seems ideal. So, the Norton's half sphere, is pretty darn good.
 
comnoz said:
Triumphs and Nortons are pretty similar in their power producing capability. Triumphs with their steeper valve angles and taller chambers have a breathing advantage over a Norton but a Norton's shallower chamber has better swirl and combustion efficiency. Tim' s Triumph goes very well mainly because Tim is a sharp tuner and has spent many hours getting it right. Jim
hi jim,where do you get triumphs have steeper valve angles than nortons,every tri motor ive had the valves are allmost laid on their back,aprox 45 deg from vertical,and where does the breathing advantage come from,not only norton has steeper valves but downdraft too and a shallower chamber,i value your experience and knowledge and look forward to your posts
 
Chris expanded the mystery why Tim's Triumph so excels. New head design?
BI engines must mostly rely on torque increases as they are so allergic to rpms.

I going to face hi CR vs octane issue, up to 17:1. Peel has about every feature mentioned so far, plus 116 octane on tap. Crossed fingers and toes its enough.
If still detonates with Powerarc ign. then I've have to thicken up spacers over .020" gasket. I've looked into water spray into exhaust as one more secret weapon in quest to shorten track lines and times.

There is another thing that's only been halfway implemented in fluid paths. Viktor Schauberger ( 1885 - 1958 ) fluid flow applied to log chutes that moved logs w/o enough water to float them. Rifled intakes and Antelope spiral exhaust is on my mind.

http://www.rexresearch.com/schaub/schaub.htm
Pistons - flat or domed?

Pistons - flat or domed?
 
hobot said:
Chris expanded the mystery why Tim's Triumph so excels. New head design?
BI engines must mostly rely on torque increases as they are so allergic to rpms.

I going to face hi CR vs octane issue, up to 17:1. Peel has about every feature mentioned so far, plus 116 octane on tap. Crossed fingers and toes its enough.
If still detonates with Powerarc ign. then I've have to thicken up spacers over .020" gasket. I've looked into water spray into exhaust as one more secret weapon in quest to shorten track lines and times.

There is another thing that's only been halfway implemented in fluid paths. Viktor Schauberger ( 1885 - 1958 ) fluid flow applied to log chutes that moved logs w/o enough water to float them. Rifled intakes and Antelope spiral exhaust is on my mind.

what?
 
chris plant said:
comnoz said:
Triumphs and Nortons are pretty similar in their power producing capability. Triumphs with their steeper valve angles and taller chambers have a breathing advantage over a Norton but a Norton's shallower chamber has better swirl and combustion efficiency. Tim' s Triumph goes very well mainly because Tim is a sharp tuner and has spent many hours getting it right. Jim
hi jim,where do you get triumphs have steeper valve angles than nortons,every tri motor ive had the valves are allmost laid on their back,aprox 45 deg from vertical,and where does the breathing advantage come from,not only norton has steeper valves but downdraft too and a shallower chamber,i value your experience and knowledge and look forward to your posts

A triumph valve is angled more toward the associated port and therefore the airflow does not need to turn as far to exit the valve. The angle from the port into the valve pocket is one of the main choke points of any head. That is why most modern bikes have gone to a downdraught style intake. That allows for shallow chambers without the bend in the intake port. It also requires long valve stems and a tall cylinder head. If you look at the intake port on this head you will see there is hardly any turn in the intake port. It flows very well. This was a billet head I made for a Norton motor. It uses the stock Norton valve angles and shallow chambers but the head is taller and the intake ports are nearly vertical when the engine is angled like a Commando.

Pistons - flat or domed?


The fact that the valves are leaned farther away from the center of chamber in a Triumph head allow a larger valve to be fitted and still maintain room around the head of the valve for air to flow into the chamber. To install a large valve in a Norton head you compromise the area between the edge of the valve and the chamber so you don't gain as much potential airflow improvement as you would expect. Re-angling the valve on a Norton also increases the angle of the bend from the port to the valve which does not help.
I am not saying there is nothing to be gained on a Norton by going a bit larger on the intake but it is less than would be indicated by the formulas for airflow vs. valve size. Jim
 
Jim sure filled me in with the head differences and expected flow potentials.


Mark, Viktor found that configuring the entry and exist of a turbine or valve
could increase the flow speed and there the power extracted. In our heads if the
intake port could speed up flow to valve and the exhaust side flow away from valve then more power to burn even w/o changing the valves, thought that might help even more. Water does not go down a drain as fast if its not spinning into a funneling concentrating speeding up vortex swirl. To make a sharp turn with less conflicting turbulence Viktor would put ridges in to trip up the flow into vortexes that didn't resist the change of direction as much. Vortex generators are known o help semi trailers reduce drag and is one of Kenny Dreer current projects to market.
 
Hobot:
I have some some experience in aero and hydro dynamics as well as airfoil design.
I spent years working in the Wind Turbine industry.
While getting my degree in Industrial Engineering I was exposed to a lot of Schaubergers ideas including Colloidal Energy.

The "What" that I posted was for the stuff that you wrote.
Honestly, For the life of me I couldn't (and still can't) decipher it.
Is English a second language for you?
 
Dang it, I strained neck yesterday fretting over Trixie barrel and had a good nip of whiskey on way home visiting some friends to brain swelling scrambling grammar.
Sorry its not intentional. Please correct my statements and help me understand vortex flow in tubes.

Viktor grew up in Mt. forest and was fascinated by stream flows, even taking temperatures ahead of and behind rocks to find some times the extra turbulence lowered the temperature a degree or so. Not an obvious result, but clue to manipulating turbulence to him. Hm, cooling the charge while speeding and mixing it up, sounds like extra engine intake spunk to me. How could one pull it off, Viktor used rifling like ridges and fins to get it around bends better.

Pistons - flat or domed?

His first concepts were brought on by studying trout in its natural environment. He was quoted as saying:

How was it possible for this fish to stand so motionlessly, only steering itself with slight movements of its tail-fins, in this wildly torrential flow, which made my staff shake so much that I could hardly hang onto it? What forces enabled the trout to overcome its own body-weight so effortlessly and quickly, and, at the same time, overcome the specific weight of the heavy water flowing against it?

These questions inspired further investigation to study the force that allowed such effortless natural motion. Schaubergers conclusion led to his theory of natural vortices.

Schauberger's second major theory was in the structure of water. He believed that water is at its densest when cold (at +4C water anomaly point) (and at the time of a full moon), and that there are many layers in the structure of flowing water. He claimed that nature creates vortices to create equilibria. He further claimed that our current form of energy production/consumption scatters matter into disequilibrium. His studies were not approved by science at the time, even when his ideas were put into practice.[citation needed]

In 1922 for Adolf I, Prince of Schaumburg-Lippe, Schauberger designed and had built several log flumes which reduced the timber transport costs to one tenth the previous cost and allowed transport of denser than water woods such as beech and fir[3]. In 1924, Viktor Schauberger became a Public Council consultant for the log flumes for the Austrian state. He started construction of three large plants in Austria. In 1926, he undertook research at a timber flotation installation in Neuberg an der Mürz in Styria. In 1929 Schauberger submitted his first applications for patents in the fields of water engineering and turbine construction. He conducted research on how to artificially generate centripetal movement in various types of machines. He proposed a means of utilising hydroelectric power by a jet turbine. The log flumes used for timber flotation allegedly disregarded the Archimedes' principle, i.e., Schauberger was allegedly able to transport heavier-than-water objects by creating a centripetal movement (making the timber spin around its own axis, by special guiding-vanes which caused the water to spiral). Professor Philipp Forchheimer was sent to study the log flumes. Professor Forchheimer in 1930-1931 later published with Schauberger a series of articles in "Die Wasserwirtschaft", the Austrian Journal of Hydrology.[citation needed]

Pistons - flat or domed?


http://en.wikipedia.org/wiki/Viktor_Schauberger

Viktor also designed hydro electric turbines in low head flows by funneling water to speed it up and produced more power than plants with much more head and total flow volumes. Why can't we get some of that in our heads?

A lot of his insights were gained measuring stream beds and banks where it turned sharply. Sounds like head ports turning to valve seats to me.

I've read a couple books on him trying to stick with the air flow in tubes part. He found long tapered twisted tubes could flow more that plain cylinder tubes.
Sure sounds like exhaust an header application to me. How would one make those?

He went far beyond log chutes and water turbines, exceeding my comprehension to follow the principles so far.

Pistons - flat or domed?

Pistons - flat or domed?
 
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